EP 0260839 A3 19890809 - PROTECTION ARRANGEMENTS FOR COMMUNICATIONS LINES
Title (en)
PROTECTION ARRANGEMENTS FOR COMMUNICATIONS LINES
Publication
Application
Priority
CA 517830 A 19860909
Abstract (en)
[origin: EP0260839A2] A protection arrangement for a two-wire line, such as a telephone sunscriber line, includes a transformer having two primary windings and a secondary winding. The primary windings are connected in series with the wires of the line with phases such that common mode (longitudinal) currents on the line induce a current in the secondary winding, whereas loop currents do not. The induced current in the secondary winding is amplified and used to trigger a protection device, such as a triac or SCR and diode bridge arrangement, to short circuit the line for the duration of any excessive current thereon.
IPC 1-7
IPC 8 full level
H02H 7/20 (2006.01); H02H 9/04 (2006.01); H04B 3/00 (2006.01); H04M 3/18 (2006.01)
CPC (source: EP KR)
H02H 3/38 (2013.01 - KR); H02H 9/041 (2013.01 - EP); H04M 3/18 (2013.01 - EP)
Citation (search report)
- [YD] US 4408248 A 19831004 - BULLEY RAYMOND M [US], et al
- [Y] US 3925624 A 19751209 - EARLE HAROLD WESTLY, et al
- [A] US 4051543 A 19770927 - MCLELLAN NORVEL JEFF
Designated contracting state (EPC)
DE FR GB NL SE
DOCDB simple family (publication)
EP 0260839 A2 19880323; EP 0260839 A3 19890809; CA 1281768 C 19910319; CN 1010155 B 19901024; CN 87106171 A 19880504; JP S6369330 A 19880329; KR 880004619 A 19880607
DOCDB simple family (application)
EP 87307683 A 19870828; CA 517830 A 19860909; CN 87106171 A 19870909; JP 21927587 A 19870903; KR 870009894 A 19870908